5. MAINTENANCE, ADJUSTMENTS AND CALIBRATION
Page 133 © 2002-2007 DH Instruments, a Fluke Company
If the PPC3 Hi Q-RPT or utility sensor is greater than A350K,
proceed directly to the <CAUTION:> screen below. If not, the
display is:
Config type:
1vac 2atm
Select <1vac> or <2atm> depending on whether the EXHAUST port is at vacuum or atmosphere. If the
ControlRef setting (see Section
3.5.7.2) does not correspond to your choice, you will receive an error.
The next display is:
CAUTION: About to
set nn MPa g
This display warns the user that pressure will increase to roughly 50 % of the Hi Q-RPT default range.
Press [ENT] to continue if it is safe for PPC3 to set the indicated pressure.
<CFG> flashes in the lower right corner of the display. PPC3 pulses and slews pressure. After about ten
minutes, the user is asked whether or not to save the new configuration. If the CONFIG function ran
completely and without incident, select <1Yes>. Select <2No> to return to the MAIN RUN screen with no
change to the pressure control coefficients.
If the PPC3 has a Hi Q-RPT less than or equal to A350K, repeat the configuration routine in the other
operating mode (<1vac> or <2atm>). If you never use the PPC3 in one of the two conditions, it is not
necessary to configure it in that condition.
The configuration routine must be run with NO external volume connected to the PPC3 (TEST(+) port
plugged) unless a known minimum test volume is always connected. After configuring with a volume
connected to the TEST(+) port, controlling pressure with a lower volume may result in poor pressure
control.
The effect of the CONFIG function can be eliminated and control coefficients returned to factory
defaults by pressing [SPECIAL], <4Internal>, <1Config>, <1factory>.
5.6 OVERHAUL
If calibration of the reference pressure transducers (Q-RPT) is included as part of the overhaul
procedure, the calibration procedure should be performed last.
Any or all of the following items may be included as part of a system maintenance overhaul:
• Disassemble pressure control module filters and clean filter elements. Replace, if necessary.
• Clean front panel.
• Clean threads of rear panel fittings. Check for damage and replace, if necessary.
• Check that rear panel cooling fan operates when PPC3 is ON.
• Check that internal screws, bolts and nuts are tight.
• Verify that internal barometer, if present, reads atmospheric pressure within ± 0.1 kPa (0.015 psi).
Adjust if necessary (see Section 5.3)
• Verify that utility sensor, if present, indicates pressure with ± 0.1 % FS over its range. Adjust if
necessary (see Section 5.4).
• Pressurize PPC3 to 90 % of maximum pressure and leak test. Use [LEAK CK] function (see Section 3.3.9).
Leak rate, after stabilization, should not exceed 0.001 % of maximum pressure/ second.
• Check the PPC3 controls within specifications over its range (see Section 1.2.3).
• Perform calibration of Q-RPTs if necessary (see Section 5.2).
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